diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index eac00c7..631319f 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -5,8 +5,6 @@ name: CI
 # Controls when the action will run.
 on:
   # Triggers the workflow on push or pull request events but only for the master branch
-  push:
-    branches: [main]
   pull_request:
     branches: [main]
 
@@ -137,10 +135,18 @@ jobs:
       - name: Run tests
         run: |
           export PYTHONPATH="$PWD/build"
-          mpirun -np 1 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests --ignore=tests/test_hmatrix.py --ignore=tests/test_logger.py
-          mpirun -np 2 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests --ignore=tests/test_hmatrix.py --ignore=tests/test_logger.py
-          mpirun -np 3 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests --ignore=tests/test_hmatrix.py --ignore=tests/test_logger.py
-          mpirun -np 4 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests --ignore=tests/test_hmatrix.py --ignore=tests/test_logger.py
+          mpirun -np 1 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_cluster.py
+          mpirun -np 2 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_cluster.py
+          mpirun -np 3 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_cluster.py
+          mpirun -np 4 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_cluster.py
+          mpirun -np 1 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_distributed_operator.py
+          mpirun -np 2 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_distributed_operator.py
+          mpirun -np 3 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_distributed_operator.py
+          mpirun -np 4 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_distributed_operator.py
+          mpirun -np 1 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_ddm_solver.py
+          mpirun -np 2 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_ddm_solver.py
+          mpirun -np 3 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_ddm_solver.py
+          mpirun -np 4 ${{ matrix.MPIEXEC_PREFLAGS }} python3 -m pytest tests/test_ddm_solver.py
           python3 -m pytest tests/test_hmatrix.py
           python3 -m pytest tests/test_logger.py
 
@@ -161,8 +167,18 @@ jobs:
       - name: Generate coverage reports
         if: matrix.CODE_COVERAGE == 'ON'
         run: |
-          lcov --ignore-errors mismatch --capture --base-directory ./ --directory build/ --output-file coverage.info
-          lcov --remove  coverage.info '/usr/*' '*/hpddm/*' '*/pybind11/*' '*/lib/htool/*' --output-file  ../coverage.info
+          # Capture coverage: both MPI (.gcda in /tmp/gcov-mpi) and serial (.gcda in build/)
+          lcov --ignore-errors mismatch \
+               --capture \
+               --base-directory $(pwd) \
+               --directory build \
+               --output-file coverage.info
+
+          # Exclude third-party and system paths
+          lcov --remove coverage.info '/usr/*' '*/hpddm/*' '*/pybind11/*' '*/lib/htool/*' --output-file filtered.info
+
+          # Convert absolute paths to relative paths for Codecov
+          lcov --extract filtered.info "${PWD}/src/*" --output-file coverage.info
 
       - uses: actions/upload-artifact@v4
         with:
@@ -180,9 +196,9 @@ jobs:
           fetch-depth: 0
       - uses: actions/download-artifact@v4
       - name: Upload coverage report
-        uses: codecov/codecov-action@v4
+        uses: codecov/codecov-action@v5
         with:
           fail_ci_if_error: true
-          file: ./coverage.info
+          files: ./coverage.info
           token: ${{ secrets.CODECOV_TOKEN }}
           verbose: true
diff --git a/src/htool/misc/logger.hpp b/src/htool/misc/logger.hpp
index 3f5d72d..1aa09da 100644
--- a/src/htool/misc/logger.hpp
+++ b/src/htool/misc/logger.hpp
@@ -29,13 +29,11 @@ class PythonLoggerWriter : public htool::IObjectWriter {
         case htool::LogLevel::INFO:
             logger.attr("info")(message);
             break;
-        default:
-            break;
         }
     }
-
-    void set_log_level(htool::LogLevel log_level) override {
-    }
+    // LCOV_EXCL_START
+    void set_log_level(htool::LogLevel log_level) override {}
+    // LCOV_EXCL_STOP
 };
 
 #endif
diff --git a/tests/conftest.py b/tests/conftest.py
index 07bb177..ed640fb 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -268,6 +268,17 @@ def local_operator(request, generator, cluster, geometry):
                     False,
                 )
             )
+            assert (
+                result[1][-1].local_target_renumbering.size
+                == target_local_cluster.get_size()
+            )
+            assert (
+                result[1][-1].local_source_renumbering.size
+                == source_cluster.get_size()
+                - source_local_cluster.get_size()
+                - source_local_cluster.get_offset()
+            )
+
         if request.param == "LocalAndExtraDiagonal":
             result[0] = "LocalAndExtraDiagonal"
             result[1].append(
@@ -277,7 +288,6 @@ def local_operator(request, generator, cluster, geometry):
                     Htool.LocalRenumbering(source_local_cluster),
                 )
             )
-
         return result
     else:
         return None
diff --git a/tests/test_distributed_operator.py b/tests/test_distributed_operator.py
index 1ac6117..2fc4b05 100644
--- a/tests/test_distributed_operator.py
+++ b/tests/test_distributed_operator.py
@@ -96,6 +96,11 @@ def test_distributed_operator(
     Y_2 = generator.mat_mat(X)
     assert np.linalg.norm(Y_1 - Y_2) / np.linalg.norm(Y_2) < epsilon
 
+    X = np.asfortranarray(np.random.rand(nb_cols, 1))
+    Y_1 = distributed_operator @ X
+    Y_2 = generator.mat_mat(X)
+    assert np.linalg.norm(Y_1 - Y_2) / np.linalg.norm(Y_2) < epsilon
+
     # Test sub matrix vector product
     test_offset = int(nb_cols / 10)
     test_size = int(nb_cols / 10)